The recent death of a 4-year-old New Jersey boy was the nation's first fatality directly caused by enterovirus D68 (EV-D68) in the current outbreak, according to media reports today, while the national count of EV-D68 cases jumped to 594.

The new total reported by the Centers for Disease Control and Prevention (CDC) today is an increase of 56 from the 538 cases reported Oct 3. The number of affected states stayed the same, at 43.

The virus, uncommon until recently, typically causes only cold-like symptoms, but some children experience a severe illness with breathing difficulties. Almost all the recent cases involved children, many of them with a history of asthma.

In Hamilton, N.J., 4-year-old Eli Waller died on Sep 25, and the CDC determined afterward that he was infected with EV-D68, according to multiple media reports. The reports said he had stayed home from school with a case of pink eye, and he went to sleep and never woke up.

"He had no signs of any illness that night, and his passing was sudden and shocking," said Jeffrey Plunkett, a Hamilton, N.J., health officer, as quoted by ABC News.

The ABC story said the Mercer County medical examiner determined that Eli had brain and lymph node swelling caused by EV-D68 and that his death was directly related to the infection.

Possible 2nd case at school

Media stories also said a second child at the school where Eli attended a preschool program has tested positive for the virus. The Times of Trenton (N.J.) identified the school as Yardville Elementary. Stories said school officials held a meeting last night to answer parents' questions about the virus.

In an Oct 3 press release about the death, New Jersey Health Commissioner Mary E. O'Dowd said the child had tested positive for EV-D68, but at that time it was not yet clear if the virus played a direct role or was a contributing factor in the death.

Last week the CDC said four people who recently died were infected with EV-D68, but it was not clear what role the virus played. Also, Rhode Island officials said last week that a 10-year-old girl who had died of a Staphylococcus aureus infection also was infected with EV-D68.

The CDC said that about half of specimens from patients with severe respiratory illness tested by CDC labs have come back positive for EV-D68. About a third have tested positive for other enteroviruses or rhinoviruses.

The CDC and others also have been looking into a possible association of the virus with a polio-like illness in children in Colorado and a few other states.